Personal computers have a wide variety of uses. One of the most common uses is as a word processor, a device that allows electronic creation and manipulation of documents, such as letters, resumes, research papers, and legal briefs. Another common use is to communicate with other computers via a network, such as, the Internet—a worldwide network of computers interconnected through public and private communication systems. Recent years have witnessed the convergence of these seemingly distinct uses through the World Wide Web.
The term “World Wide Web” generally refers to a portion of the Internet that encompasses electronically linked documents written with special internal format codes, such as the hypertext markup language (HTML.) Within the Web, each document has a unique identifier, known as a uniform resource locator (or URL) which serves as its unique electronic address. The URL for any document can be included as part of one or more other Web documents, providing a selectable link—more precisely, a hyperlink—between the documents. With proper computer software and Internet access, a user of a document including a hyperlink to another document can select the hyperlink, which is normally displayed in a contrasting color from other text in the document, using conventional point-and-click commands.
Selecting the hyperlink connects the computer hosting the document with the hyperlink to the computer hosting the document associated with the hyperlink (the hyperlinked document), and ultimately allows the user who invoked the hyperlink to view the hyperlinked document, which can be located anywhere in the world. The hyperlinked document can also contain hyperlinks to other documents, allowing the user to “hop” around the world viewing various hyperlinked documents at will.
Hyperlinks are typically inserted into documents manually or automatically. Manual insertion often occurs through a document editor or word processing program, such as Microsoft Word 6.0 or Corel WordPerfect 8.0, that includes a hyperlink definition capability. More particularly, manual insertion requires a user to select text in a document, to indicate a desire to associate a hyperlink with the text, and then to enter the URL for the document to hyperlink to. For example, a user writing a paper on the American Revolution might select text referring to George Washington and insert the URL for a document providing a brief biography of George Washington. However, manual insertion of hyperlinks can be not only tedious and time-consuming, but also error prone.
Conventionally, one of few methods for automatic insertion of hyperlinks is through execution of an index-generation program, which builds an alphabetical “back-of-the-book” type index for a document. For example, WebAnchor (TM) software from Iconovex Corporation of Bloomington, Minn., uses semantic (meaning-based) analysis to extract key words, phrases and ideas from one or more documents and then automatically builds an index that includes hyperlinks to those extracted words, phrases, and ideas in the documents. A user viewing the index can select a word, phrase, or idea in the index and then hyperlink to the specific portion of the document containing it. (See also U.S. Pat. No. 5,708,825, entitled Automatic Summary Page Creation and Hyperlink Generation, filed May 26, 1995 and issued Jan. 13, 1998.)
One problem in using conventional manually and automatically generated hyperlinks concerns their longevity. In particular, as documents containing hyperlinks age, many hyperlinks become out dated and ineffective because the documents they point to have been deleted, revised, or moved to other computers, or because the computer hosting a hyperlinked document no longer recognizes or understands one or more parts of the URL for the hyperlink. Whatever the reason, attempting to execute or invoke these ineffective hyperlinks results in an error message, such as “file not found,” being shown to the user instead of the desired document. Although the user, can update or replace the URL associated with an ineffective hyperlink, this can be inconvenient and time consuming, particularly in documents with many hyperlinks.
Another problem with manually and automatically generated hyperlinks concerns the time or cost of accessing the hyperlinked documents. In particular, hyperlinks are typically generated without regard to either the time needed to execute a hyperlink or the charges a user may incur in hyperlinking to specific host computers. This is especially troublesome when a user wastes time or incurs charges hyperlinking to a document on another computer system that also exists on her computer system.
Accordingly, there is a need for hyperlinks that are less likely to become ineffective over time and that are generated with concern for user preferences, such as connection time and cost.